Atoms

Wavelength of the particle whose momentum is p

• $\frac{\mathrm{h}}{\mathrm{p}}$

• hp

• $\frac{\mathrm{p}}{\mathrm{h}}$

• p + h

In nth orbit of hydrogen atom energy $\mathrm{E} = \frac{- 13.6}{{\mathrm{n}}^2} \mathrm{eV}$, then energy required to displace  electrons from n = 1 to n = 2 is

• - 10.2 eV

• 3.4 eV

• - 13.6 eV

• 1.51 eV

The minimum energy to ionize an atom is the energy required to

• add one electron to the atom

• excite the atom from its ground state to its excited state

• remove one outer most electron from the atom

• remove one inner most electron from the atom

In hydrogen atom, the electron in a given orbit has total energy -1.5 eV. The potential energy is

• 1.5 eV

• - 1.5 eV

• 3.0 eV

• - 3.0 eV

The wavelength of first Lyman series in the transition from n = 2 to n = 1 is

• 110 nm

• 120 nm

• 122 nm

• 125 nm

λ₁, λ₂, λ₃ are de-Broglie wavelengths of electron, proton and $\mathrm{\alpha }$ - particle. If they are accelerated by same potential, then

• λ₁ < λ₂ < λ₃

• λ₁ >λ₂ > λ₃

• λ₁ < λ₂ > λ₃

• λ₁ > λ₂ < λ₃

Which energy state of triply ionized beryllium Be³⁺ has the same orbital radius as that of ground state of hydrogen atom ?

• n = 8 state

• n = 5 state

• n = 4 state

• n = 2 state

In Bohr's model of hydrogen atom, the electron circulates around the nucleus in a path of radius 5 x 10^-11 m at a frequency of 6.8 x 10¹⁵ Hz. The value of magnetic field and equivalent magnetic moment will be

• 15.4 T and 8.9 x 10^-24 A-m²

• 13.4 T and 8.9 x 10^-24 A-m²

• 18.4 T and 9.8 x 10^-24 A-m²

• 13.4 T and 9.8 x 10^-24 A-m²

Which element has K_{$\mathrm{\alpha }$} line of wavelength in 1.785 $\stackrel{°}{\mathrm{A}}$ ?

• Copper

• Cobalt

• Sodium

• Aluminium

The energy levels of a certain atom are represented in the figure given below. During the transition from 2E to E level, a photon of wavelength is emitted. The wavelength of photon produced during transition from 4 / 3E level to E will be

• $3\mathrm{\lambda }$

• $\frac{\mathrm{\lambda }}{3}$

• $\frac{3\mathrm{\lambda }}{3}$

• $\frac{4\mathrm{\lambda }}{3}$